add a yaml exmaple for type nodeport

Author: AlphaWong

content/en/docs/concepts/services-networking/service.md

@@ -534,6 +534,25 @@ to just expose one or more nodes' IPs directly.
 Note that this Service is visible as `<NodeIP>:spec.ports[*].nodePort`
 and `.spec.clusterIP:spec.ports[*].port`. (If the `--nodeport-addresses` flag in kube-proxy is set, <NodeIP> would be filtered NodeIP(s).)
 
+For example:
+```yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: my-service
+spec:
+  type: NodePort
+  selector:
+    app: MyApp
+  ports:
+    - port: 80
+      # By default and for convenience, the targetPort is set to the same value as the port field.
+      targetPort: 80
+      # `targetPort` is the port of pod, you would like to expose
+      NodePort: 30007
+      # `NodePort` is the port of node, you would like to expose
+```
+
 ### Type LoadBalancer {#loadbalancer}
 
 On cloud providers which support external load balancers, setting the `type`